pow-buster 0.2.0

SIMD accelerated solver for mCaptcha/Anubis/Cerberus/go-away/Cap.js PoW challenges, features comprehensive coverage for Anubis challenge workflow.
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
use crate::{Align64, message::CerberusMessage};
use core::arch::x86_64::*;

static LANE_ID_STR_COMBINED_LE_HI: Align64<[u32; 1000 / 8 * 8]> = {
    let mut out = [0; 1000 / 8 * 8];
    let mut i = 0;
    while i < 1000 / 8 * 8 {
        let mut copy = i;
        let mut ds = [0; 4];
        let mut j = 0;
        while j < 3 {
            ds[j] = (copy % 10) as u8 + b'0';
            copy /= 10;
            j += 1;
        }
        out[i] = u32::from_be_bytes(ds);
        i += 1;
    }
    Align64(out)
};

#[expect(dead_code)]
mod static_asserts {
    use super::*;

    const ASSERT_LANE_ID_STR_COMBINED_LE_HI_0: [(); 1] =
        [(); (LANE_ID_STR_COMBINED_LE_HI.0[0] == u32::from_be_bytes(*b"000\x00")) as usize];

    const ASSERT_LANE_ID_STR_COMBINED_LE_HI_1: [(); 1] =
        [(); (LANE_ID_STR_COMBINED_LE_HI.0[1] == u32::from_be_bytes(*b"100\x00")) as usize];

    const ASSERT_LANE_ID_STR_COMBINED_LE_HI_123: [(); 1] =
        [(); (LANE_ID_STR_COMBINED_LE_HI.0[123] == u32::from_be_bytes(*b"321\x00")) as usize];
}

cpufeatures::new!(avx2, "avx2");

#[derive(Debug, Copy, Clone)]
/// Required features for AVX-2 solver.
pub struct RequiredFeatures;

impl Default for RequiredFeatures {
    fn default() -> Self {
        Self
    }
}

impl crate::solver::CpuIDToken for RequiredFeatures {
    fn get() -> bool {
        avx2::get()
    }
}

/// AVX-2 Cerberus solver.
///
/// Current implementation: 9-digit out-of-order kernel with dual-wavefront 8 way SIMD and quarter-round hotstart granularity.
pub struct CerberusSolver {
    message: CerberusMessage,
    attempted_nonces: u64,
    limit: u64,
}

impl From<CerberusMessage> for CerberusSolver {
    fn from(message: CerberusMessage) -> Self {
        Self {
            message,
            attempted_nonces: 0,
            limit: !0,
        }
    }
}

impl CerberusSolver {
    /// Set the limit.
    pub fn set_limit(&mut self, limit: u64) {
        self.limit = limit;
    }

    /// Get the attempted nonces.
    pub fn get_attempted_nonces(&self) -> u64 {
        self.attempted_nonces
    }
}

impl CerberusSolver {
    #[inline(never)]
    #[target_feature(enable = "avx2")]
    fn solve_decimal_impl<
        const CENTER_WORD_IDX: usize,
        const LANE_ID_WORD_IDX: usize,
        const CONSTANT_WORD_COUNT: usize,
    >(
        &mut self,
        msg_tpl: Align64<[u32; 16]>,
        target: u64,
        mask: u64,
    ) -> Option<(u64, u64)> {
        debug_assert_eq!(target, 0);

        let CerberusMessage::Decimal(message) = &self.message else {
            return None;
        };

        // inform LLVM that padding is guaranteed to be zero
        let mut msg = Align64([0u32; 16]);
        msg.0[..=CENTER_WORD_IDX + 1].copy_from_slice(&msg_tpl.0[..=CENTER_WORD_IDX + 1]);
        let prepared_state = crate::blake3::ingest_message_prefix(
            *message.prefix_state,
            &msg[..CONSTANT_WORD_COUNT],
            0,
            message.salt_residual_len as u32 + 9,
            message.flags,
        );

        for lane_id_idx in 0..(LANE_ID_STR_COMBINED_LE_HI.len() / 8) {
            if self.attempted_nonces >= self.limit {
                return None;
            }
            unsafe {
                let mut lane_id_value = _mm256_load_si256(
                    LANE_ID_STR_COMBINED_LE_HI
                        .as_ptr()
                        .add(lane_id_idx * 8)
                        .cast(),
                );
                if CENTER_WORD_IDX < LANE_ID_WORD_IDX {
                    lane_id_value = _mm256_srli_epi32(lane_id_value, 8);
                }

                let state_base =
                    core::array::from_fn(|i| _mm256_set1_epi32(prepared_state[i] as _));
                let patch =
                    _mm256_or_epi32(_mm256_set1_epi32(msg[LANE_ID_WORD_IDX] as _), lane_id_value);
                let maskv = _mm256_set1_epi32((mask >> 32) as _);

                for (i, word) in crate::strings::DIGIT_LUT_10000_LE_EVEN.iter().enumerate() {
                    msg[CENTER_WORD_IDX] = *word;

                    let mut state = state_base;

                    crate::blake3::avx2::compress_mb8::<CONSTANT_WORD_COUNT, LANE_ID_WORD_IDX>(
                        &mut state, &msg, patch,
                    );

                    let s0 = state[0];
                    let sm0 = _mm256_and_si256(s0, maskv);
                    let cmp0 = _mm256_cmpeq_epi32(sm0, _mm256_setzero_si256());
                    let nothit0 = _mm256_testz_si256(cmp0, cmp0);
                    self.attempted_nonces += 8;

                    if nothit0 == 0 {
                        crate::unlikely();
                        let mut dump = Align64([0u32; 8]);
                        let word_idx = i as u64 * 2;

                        _mm256_store_si256(dump.as_mut_ptr().cast(), sm0);

                        let success_lane_idx = dump.0.iter().position(|x| *x == 0).unwrap();

                        return Some((word_idx, lane_id_idx as u64 * 8 + success_lane_idx as u64));
                    }

                    msg[CENTER_WORD_IDX] |= u32::from_be_bytes([1, 0, 0, 0]);

                    state = state_base;
                    crate::blake3::avx2::compress_mb8::<CONSTANT_WORD_COUNT, LANE_ID_WORD_IDX>(
                        &mut state, &msg, patch,
                    );

                    let s1 = state[0];
                    let sm1 = _mm256_and_si256(s1, maskv);
                    let cmp1 = _mm256_cmpeq_epi32(sm1, _mm256_setzero_si256());
                    let nothit1 = _mm256_testz_si256(cmp1, cmp1);
                    self.attempted_nonces += 8;

                    if nothit1 == 0 {
                        crate::unlikely();
                        let mut dump = Align64([0u32; 8]);
                        let word_idx = i as u64 * 2 + 1;

                        _mm256_store_si256(dump.as_mut_ptr().cast(), sm1);

                        let success_lane_idx = dump.0.iter().position(|x| *x == 0).unwrap();

                        return Some((word_idx, lane_id_idx as u64 * 8 + success_lane_idx as u64));
                    }
                }
            }
        }
        None
    }

    #[inline(never)]
    #[target_feature(enable = "avx2")]
    fn solve_binary_impl(&mut self, target: u64, mask: u64) -> Option<u64> {
        debug_assert_eq!(target, 0);

        let CerberusMessage::Binary(message) = &self.message else {
            return None;
        };

        let mut msg = [0; 16];
        msg[0] = message.first_word;
        let prepared_state = crate::blake3::ingest_message_prefix(
            *message.midstate,
            &msg[..1],
            0,
            8,
            crate::blake3::FLAG_CHUNK_END | crate::blake3::FLAG_ROOT,
        );
        unsafe {
            let state_base = core::array::from_fn(|i| _mm256_set1_epi32(prepared_state[i] as _));
            let mut nonce = _mm256_setr_epi32(0, 1, 2, 3, 4, 5, 6, 7);
            let increment_nonce = _mm256_set1_epi32(8);
            let masks = (mask >> 32) as u32;
            let maskv = _mm256_set1_epi32(masks as i32);
            for rep in 0..=(u32::MAX / 8) {
                let mut state = state_base;
                crate::blake3::avx2::compress_mb8::<1, 1>(&mut state, &msg, nonce);
                self.attempted_nonces += 8;
                let m = _mm256_and_si256(state[0], maskv);
                let cmp = _mm256_cmpeq_epi32(m, _mm256_setzero_si256());
                let nothit = _mm256_testz_si256(cmp, cmp);
                if nothit == 0 {
                    crate::unlikely();
                    let mut dump = Align64([0u32; 8]);
                    _mm256_store_si256(dump.as_mut_ptr().cast(), state[0]);
                    let success_lane_idx = dump.0.iter().position(|x| *x & masks == 0).unwrap();
                    return Some(
                        (rep * 8 + success_lane_idx as u32) as u64
                            | (message.first_word as u64) << 32,
                    );
                }
                nonce = _mm256_add_epi32(nonce, increment_nonce);
                if self.attempted_nonces >= self.limit {
                    return None;
                }
            }
        }
        None
    }
}

impl crate::solver::Solver for CerberusSolver {
    fn set_limit(&mut self, limit: u64) {
        self.limit = limit;
    }

    fn get_attempted_nonces(&self) -> u64 {
        self.attempted_nonces
    }

    fn solve_nonce_only<const TYPE: u8>(&mut self, target: u64, mask: u64) -> Option<u64> {
        match &self.message {
            CerberusMessage::Binary(_) => unsafe { self.solve_binary_impl(target, mask) },
            CerberusMessage::Decimal(message) => {
                // two digits as lane ID, N=\x00, ? is prefix
                // position % 4 =0: |1234|5678|NNN9
                // position % 4 =1: |123?|4567|NN89
                // position % 4 =2: |12??|3456|N789
                // position % 4 =3: |1???|2345|6789

                let center_word_idx = message.salt_residual_len / 4 + 1;
                let nonce_addend = message.nonce_addend;
                let salt_residual = message.salt_residual;
                let salt_residual_len = message.salt_residual_len;
                let position_mod = message.salt_residual_len % 4;

                for resid0 in 0..10u64 {
                    for resid1 in 0..10u64 {
                        if self.attempted_nonces >= self.limit {
                            return None;
                        }
                        let mut msg = salt_residual;

                        match position_mod {
                            0 => {
                                msg[salt_residual_len] = resid0 as u8 + b'0';
                                msg[salt_residual_len + 8] = resid1 as u8 + b'0';
                            }
                            1 => {
                                msg[salt_residual_len + 7] = resid0 as u8 + b'0';
                                msg[salt_residual_len + 8] = resid1 as u8 + b'0';
                            }
                            2 => {
                                msg[salt_residual_len] = resid0 as u8 + b'0';
                                msg[salt_residual_len + 1] = resid1 as u8 + b'0';
                            }
                            3 => {
                                msg[salt_residual_len] = resid0 as u8 + b'0';
                                msg[salt_residual_len + 8] = resid1 as u8 + b'0';
                            }
                            _ => unreachable!(),
                        }

                        let msg = Align64(core::array::from_fn(|i| {
                            u32::from_le_bytes([
                                msg[i * 4],
                                msg[i * 4 + 1],
                                msg[i * 4 + 2],
                                msg[i * 4 + 3],
                            ])
                        }));

                        macro_rules! dispatch {
                            ($center_word_idx:literal) => {
                                if position_mod < 2 {
                                    unsafe {
                                        self.solve_decimal_impl::<$center_word_idx, { $center_word_idx - 1 }, {$center_word_idx - 1}>(
                                        msg, target, mask,
                                        )
                                    }
                                } else {
                                    unsafe {
                                        self.solve_decimal_impl::<$center_word_idx, { $center_word_idx + 1 }, $center_word_idx>(
                                        msg, target, mask,
                                        )
                                    }
                                }
                            };
                        }

                        if let Some((middle_word, success_lane_idx)) = match center_word_idx {
                            1 => dispatch!(1),
                            2 => dispatch!(2),
                            3 => dispatch!(3),
                            4 => dispatch!(4),
                            5 => dispatch!(5),
                            6 => dispatch!(6),
                            7 => dispatch!(7),
                            8 => dispatch!(8),
                            9 => dispatch!(9),
                            10 => dispatch!(10),
                            11 => dispatch!(11),
                            12 => dispatch!(12),
                            13 => dispatch!(13),
                            14 => dispatch!(14),
                            15 => dispatch!(15),
                            _ => unreachable!(),
                        } {
                            let output_nonce = nonce_addend
                                + match position_mod {
                                    0 => {
                                        10 * middle_word
                                            + 100_000 * success_lane_idx
                                            + 100_000_000 * resid0
                                            + resid1
                                    }
                                    1 => {
                                        100 * middle_word
                                            + 1_000_000 * success_lane_idx
                                            + 10 * resid0
                                            + resid1
                                    }
                                    2 => {
                                        1000 * middle_word
                                            + success_lane_idx
                                            + 100_000_000 * resid0
                                            + 10_000_000 * resid1
                                    }
                                    3 => {
                                        10000 * middle_word
                                            + 10 * success_lane_idx
                                            + 100_000_000 * resid0
                                            + resid1
                                    }
                                    _ => unreachable!(),
                                };

                            return Some(output_nonce);
                        }
                    }
                }

                None
            }
        }
    }

    fn solve<const TYPE: u8>(&mut self, target: u64, mask: u64) -> Option<(u64, [u32; 8])> {
        if let Some(nonce) = self.solve_nonce_only::<TYPE>(target, mask) {
            match &self.message {
                CerberusMessage::Decimal(message) => {
                    let mut msg = message.salt_residual;

                    let mut nonce_copy = nonce;
                    for i in (0..9).rev() {
                        msg[message.salt_residual_len + i] = (nonce_copy % 10) as u8 + b'0';
                        nonce_copy /= 10;
                    }

                    let mut msg = core::array::from_fn(|i| {
                        u32::from_le_bytes([
                            msg[i * 4],
                            msg[i * 4 + 1],
                            msg[i * 4 + 2],
                            msg[i * 4 + 3],
                        ])
                    });

                    let hash = crate::blake3::compress8(
                        &message.prefix_state,
                        &mut msg,
                        0,
                        message.salt_residual_len as u32 + 9,
                        message.flags,
                    );

                    Some((nonce, hash))
                }
                CerberusMessage::Binary(message) => {
                    let mut msg = [0; 16];
                    msg[0] = message.first_word;
                    msg[1] = nonce as u32;
                    let hash = crate::blake3::compress8(
                        &message.midstate,
                        &msg,
                        0,
                        8,
                        crate::blake3::FLAG_CHUNK_END | crate::blake3::FLAG_ROOT,
                    );
                    Some((msg[1] as u64 | (msg[0] as u64) << 32, hash))
                }
            }
        } else {
            None
        }
    }
}

#[cfg(target_feature = "avx2")]
#[cfg(test)]
mod tests {
    use crate::message::{CerberusBinaryMessage, CerberusDecimalMessage};

    use super::*;

    #[test]
    fn test_solve_cerberus_decimal() {
        for i in 0..=1 {
            crate::solver::tests::test_cerberus_decimal_validator::<CerberusSolver, _>(|prefix| {
                Some(CerberusMessage::Decimal(CerberusDecimalMessage::new(prefix, i)?).into())
            });
        }
    }

    #[test]
    fn test_solve_cerberus_binary() {
        for i in 0..=1 {
            crate::solver::tests::test_cerberus_binary_validator::<CerberusSolver, _>(|prefix| {
                Some(CerberusMessage::Binary(CerberusBinaryMessage::new(prefix, i)).into())
            });
        }
    }
}